CN103558658B - The wiring of optical waveguide, light, opto-electric hybrid board and electronic equipment - Google Patents

Abstract

Optical waveguide of the present invention, the covering portion that there is core and adjoin with this core and arrange, wherein, described covering portion has: the region of low refractive index that refractive index contacts lower than described core and with this core; And multiple high-refractive-index regions that refractive index separates higher than this region of low refractive index and by this region of low refractive index and core, described multiple high-refractive-index regions is dispersed in described covering portion, or is fitly arranged in described covering portion.Each high-refractive-index regions is made up of the material with core identical type respectively.Each high-refractive-index regions make not incide core but not original idea incide the light generation scattering etc. of covering portion, prevent this light from arriving the phenomenon of photo detector thus, thus the quality of optical communication can be improved.

Description

The wiring of optical waveguide, light, opto-electric hybrid board and electronic equipment

The divisional application that the application is the applying date is on August 28th, 2009, application number is 200980134714.9, denomination of invention is the application of " wiring of optical waveguide, light, opto-electric hybrid board and electronic equipment ".

Technical field

The present invention relates to optical waveguide, light wiring, opto-electric hybrid board and electronic equipment.

Background technology

In recent years, utilize the optical communication of optical frequency carrier wave transmission data more and more important.In such optical communication, as mode optical frequency carrier wave being transmitted to another place from, there is optical waveguide.

This optical waveguide, such as, be made up of a pair clad and the sandwich layer be arranged between a pair clad.Sandwich layer comprises wire core and is arranged on the covering portion of these core both sides in the mode of clamping this core.Core is by forming the material that optical frequency carrier wave is transparent in fact, and clad and covering portion are made up of the material of refractive index lower than core.

Patent Document 1 discloses a kind of polymer optical wave guide, the polysilane layer that this polymer optical wave guide comprises two-layer clad (upper cladding layer and bottom clad) and is arranged between this two-layer clad, that use contains polysilane and organic peroxide polysilane composition and formed.In addition, in polysilane layer, be formed with sandwich layer (core) and be arranged on the side clad (covering portion) of these sandwich layer both sides.

In such optical waveguide, core to be surrounded lower than the clad of core and covering portion by refractive index and forms.Therefore, the light imported from the end of core is while the border with clad and covering portion carries out reflecting, and the axle along core transmits.

In addition, be configured with the light-emitting components such as semiconductor laser at the light incident side of optical waveguide, and will the core inciding optical waveguide from the light of this light-emitting component be produced.On the other hand, be configured with the photo detectors such as photodiode in the exiting side of optical waveguide, and received the light come through core transmission by photo detector.And the flashing pattern of the light that can receive according to photo detector carries out optical communication.

But when the medium adjacent of optical waveguide and low-refraction, specifically, when optical waveguide is present in air, light not only reflects on the border of core and covering portion, and reflects on the border of covering portion and air.

At this, preferably whole light of generation self-emission device are made to incide core at the light incident side of optical waveguide, but in general, because the coupling that light shaft offset or opening number occur between optical waveguide and light-emitting component is bad etc., a part of light incides covering portion sometimes.

So be incident to the light of covering portion, repeatedly reflect on the border with air, and be transmitted to terminal.And finally this light is from the terminal outgoing of covering portion, together with the light from core outgoing receive by photo detector.There are the following problems for its result: become interference wave through the light that covering portion transmission is next and reduce S/N ratio, causing the quality of optical communication to decline because of reasons such as crosstalks.

In addition, if comprise the significantly little part of refringence between core and covering portion, then the light propagated through core can escape to covering portion side from this part sometimes.This light spilt also becomes interference wave through covering portion transmission.Its result, likely causes the further reduction of optical communication quality.

Prior art document

Patent documentation

Patent documentation 1: Japanese Unexamined Patent Publication 2004-333883 publication

Summary of the invention

The object of the invention is to, thering is provided a kind of by there is the light that can make through covering portion transmission away from the device of core, the S/N ratio of flashlight can be improved and the optical waveguide of high-quality optical communication can be carried out and there is the high-performance optical wiring of described optical waveguide, opto-electric hybrid board and electronic equipment.

In order to achieve the above object, optical waveguide of the present invention, the covering portion that there is core and adjoin with this core and arrange, it is characterized in that: described covering portion has region of low refractive index and multiple high-refractive-index regions, the refractive index of this region of low refractive index lower than described core refractive index and contact with described core, the refractive index of the plurality of high-refractive-index regions higher than this region of low refractive index refractive index and separated by this region of low refractive index and described core, the plurality of high-refractive-index regions is dispersed in described covering portion, or is fitly arranged in described covering portion.

In addition, in optical waveguide of the present invention, preferred described each high-refractive-index regions is made up of the material with described core identical type respectively.

In addition, in optical waveguide of the present invention, the preferred refractive index of described each high-refractive-index regions and the refringence of described region of low refractive index are more than 0.5%.

In addition, in optical waveguide of the present invention, preferred described multiple high-refractive-index regions makes to be reflected to the direction away from described core by the light of described covering portion, or makes to carry out irregular scattering by the light of described covering portion.

In addition, in optical waveguide of the present invention, preferred described each high-refractive-index regions respectively in pelletized form.

In addition, in optical waveguide of the present invention, preferred described each granular high-refractive-index regions has concavo-convex respectively on its profile.

In addition, in optical waveguide of the present invention, preferred described each granular high-refractive-index regions is dispersed in described covering portion brokenly.

In addition, in optical waveguide of the present invention, preferred described each high-refractive-index regions is respectively in slat.

In addition, in optical waveguide of the present invention, being oriented to of the high-refractive-index regions of preferred described each slat, the axis on its length direction tilts from the vertical line of described core axis to the rear side of the working direction of the light by described core respectively.

In addition, in optical waveguide of the present invention, the angle that the axis of the high-refractive-index regions of preferred described each slat and the vertical line of described core axis are formed is 10 ~ 85 °.

In addition, in optical waveguide of the present invention, the shape of the high-refractive-index regions of preferred described each slat is elongated triangle.

In addition, in optical waveguide of the present invention, preferably the cross-sectional area of the described high-refractive-index regions in elongated triangular is in more becoming large shape gradually away from this cross-sectional area of described core.

In addition, in optical waveguide of the present invention, in the high-refractive-index regions of preferred described each slat, the extended line of the axis of its length direction and the axis of described core are mutually vertical respectively.

In addition, in optical waveguide of the present invention, the shape of the high-refractive-index regions of preferred described each slat is elongated rectangle.

In addition, in optical waveguide of the present invention, the high-refractive-index regions of preferred described each slat is configured to be parallel to each other.

In addition, in optical waveguide of the present invention, preferred described multiple high-refractive-index regions is configured to light incident side end face and the light exit side end face that can not be exposed to this optical waveguide.

In addition, in optical waveguide of the present invention, preferred described multiple high-refractive-index regions is the region formed by the manufacturing process identical with described core.

In addition, in optical waveguide of the present invention, preferably this optical waveguide has the laminated body stacking gradually ground floor, the second layer and third layer, wherein, a part for the described second layer forms described core, and the remainder of the described second layer, described ground floor and described third layer form described covering portion.

In addition, in optical waveguide of the present invention, preferred described multiple high-refractive-index regions is arranged in the described second layer.

In addition, in optical waveguide of the present invention, preferably the described core of this optical waveguide and described covering portion at least partially, are that main material is formed with norbornene polymer respectively.

In order to achieve the above object, light wiring of the present invention, is characterized in that having described optical waveguide.

In order to achieve the above object, opto-electric hybrid board of the present invention, is characterized in that, forms by electrical wiring and described light wiring mixing being equipped on substrate.

In order to achieve the above object, electronic equipment of the present invention, is characterized in that, has described opto-electric hybrid board.

Accompanying drawing explanation

Fig. 1 be represent optical waveguide of the present invention the first embodiment stereographic map (excision a part, and through and represent).

Fig. 2 is for only representing the vertical view of the sandwich layer of the optical waveguide shown in Fig. 1.

Fig. 3 is for representing the figure of light transmission path one example of the sandwich layer of transmission shown in Fig. 2.

Fig. 4 is for representing the schematic section of the manufacture method operation example of the optical waveguide shown in Fig. 1.

Fig. 5 is for representing the schematic section of the manufacture method operation example of the optical waveguide shown in Fig. 1.

Fig. 6 is for representing the schematic section of the manufacture method operation example of the optical waveguide shown in Fig. 1.

Fig. 7 is for representing the schematic section of the manufacture method operation example of the optical waveguide shown in Fig. 1.

Fig. 8 is for representing the schematic section of the manufacture method operation example of the optical waveguide shown in Fig. 1.

Fig. 9 is for representing the figure of first another configuration example of embodiment shown in Fig. 2.

Figure 10 is for representing the figure of another configuration example of the first embodiment shown in Fig. 2.

Figure 11 only represents that second of optical waveguide of the present invention is the vertical view of the sandwich layer of embodiment.

Figure 12 is for representing the figure of another configuration example of the second embodiment shown in Figure 11.

Figure 13 is the figure of the assay method for illustration of the light intensity from the outgoing of optical waveguide covering portion.

Figure 14 is the figure of the evaluation method for illustration of crosstalk.

Figure 15 is the chart representing the light intensity come through covering portion transmission.

Figure 16 is the chart of the intensity representing Crosstalk.

Figure 17 is the vertical view of the sandwich layer only representing optical waveguide in the past.

Embodiment

Below, the preferred implementation with reference to the accompanying drawings, describes optical waveguide of the present invention, light wiring, opto-electric hybrid board and electronic equipment in detail.

< first embodiment >

First, the first embodiment of optical waveguide of the present invention is described.

Fig. 1 be represent optical waveguide of the present invention the first embodiment stereographic map (excision a part, and through and represent); Fig. 2 is for only representing the vertical view of the sandwich layer of the optical waveguide shown in Fig. 1; Fig. 3 is for representing an illustration of transmission propagation path of light of sandwich layer shown in Fig. 2.Wherein, in the following description, the upside in Fig. 1 is called " on " or " top ", downside is called D score or " below "; Right side in Fig. 2,3 is called " right side " or " exiting side ", left side is called " left side " or " light incident side ".In addition, in FIG, the mode of exaggeration is adopted to be described to the thickness direction (above-below direction of each figure) of layer.

Optical waveguide 10 shown in Fig. 1, be the optical waveguide stacking gradually clad (covering portion) 11, sandwich layer 13 and clad (covering portion) 12 from the downside of Fig. 1, in sandwich layer 13, be formed with the core 14 of predetermined pattern and the side covering portion 15(covering portion adjacent with this core (waveguide passage) 14).In Fig. 1, be alternately provided with two cores 14 and three side covering portion 15.

For the optical waveguide 10 shown in Fig. 1, make the light of the core 14 inciding light incident side end face 10a carry out being totally reflected and being transferred to exiting side at the interface of core 14 with covering portion (each clad 11,12 and each side covering portion 15), above-mentioned light can be taken out from the core 14 of exiting side end face 10b thus.

In addition, as described in detail below, each side covering portion 15 comprises refractive index respectively higher than multiple high-refractive-index regions 151 in other regions (region of low refractive index) in each side covering portion 15.That is, side covering portion 151 is divided into multiple high-refractive-index regions 151 and refractive index lower than the region of low refractive index 152 of this high-refractive-index regions 151.And the multiple high-refractive-index regions 151 shown in Fig. 1 are fitly arranged in each side covering portion 15.

For the refringence in core 14 and side covering portion 15 between region of low refractive index 152, there is no particular limitation, but be preferably more than 0.5%, is more preferably more than 0.8%.On the other hand, higher limit is not set especially, but be preferably 5.5%.If refringence is lower than above-mentioned lower limit, then reduces optical transport effect sometimes, in addition, even if exceed above-mentioned higher limit, higher light transmissioning efficiency can not be expected.

In addition, when the refractive index of core 14 being set to A, when the refractive index of region of low refractive index 152 is set to B, above-mentioned refringence can represent by following formula.

Refringence (%)=︳ A/B-1 ︳ × 100

In addition, in the formation shown in Fig. 1, the core 14 formed is linearly under the state of overlooking, but also can bend in midway, branch etc., its shape can have any shape.In addition, if use as the manufacture method of optical waveguide 10 described later, then can easily and high dimensional accuracy ground forms complexity and the core 14 of arbitrary shape.

In addition, the shape of cross section of core 14 is the quadrilateral as square or rectangle (rectangle) etc.

To the width of core 14 and height, there is no particular limitation, but be preferably 1 ~ 20 μm respectively, is more preferably 5 ~ 100 μm, more preferably 10 ~ 60 μm.

This core 14 is made up of the material of refractive index higher than the region of low refractive index 152 in side covering portion 15, and is also made up of higher than the material of clad 11,12 refractive index.

For each constituent material of core 14, side covering portion 15 and clad 11,12, as long as the material of above-mentioned refringence can be produced respectively, there is no particular limitation, in the present embodiment, core 14 and side covering portion 15 are made up of same material (sandwich layer 13), and core 14 is embodied by the difference of the chemical constitution of each material with the refringence of region of low refractive index 152 and the refringence of high-refractive-index regions 151 and region of low refractive index 152.

For the constituent material of sandwich layer 13, as long as in fact to the material of transmission at the optical transparency of core 14, any materials can be used, specifically, acrylic resin, methacrylic resin, polycarbonate, polystyrene, epoxy resin, polyamide, polyimide, polybenzoxazole, polysilane, polysilazane can be used, in addition, except the various resin materials of the such as cyclic olefin such as benzocyclobutane vinyl resin or norbornene resin resinoid etc., the glass material etc. of quartz glass, borosilicate glass etc. can be used.

Wherein, as present embodiment, in order to the difference by chemical constitution embodies refringence, the material that irradiation (or by the further heating) refractive index preferably by ultraviolet, electron ray isoreactivity energy line changes.

As such material, such as can enumerate by the irradiation of active energy ray or heating cut off at least partially key or at least partially functional group depart from, the chemical constitution material that can change thus.

Specifically, as the silane-based resins of polysilane (as Polymethylphenylsilane), polysilazane (as Perhydropolysilazane) etc., or as the base resin of the material changed with said structure, can enumerate the side chain of molecule or end have functional group below the resin of (1) ~ (6).(1) addition (being total to) polymerization is carried out to norbornene-type monomers and addition (being total to) polymkeric substance of norbornene-type monomers that obtains; (2) addition copolymer of norbornene-type monomers and ethene or alpha-olefines; (3) norbornene-type monomers and non-conjugated diene and as required with the addition copolymer of other monomers; (4) open loop (being total to) polymkeric substance of norbornene-type monomers and the resin that as required this (being total to) hydrogenation of polymer obtained; (5) the ring opening copolymer thing of norbornene-type monomers and ethene or alpha-olefines and the resin that as required this (being total to) hydrogenation of polymer obtained; (6) norbornene-type monomers and non-conjugated diene or the norbornene resin with the ring opening copolymer thing of other monomers and the resin that obtains this (being total to) hydrogenation of polymer as required etc., in addition, polymerization light solidification reactivity monomer can also be enumerated and the acrylic resin, the epoxy resin that obtain.

Particularly preferably norbornene resin in these materials.These norbornene polymers, such as by ring opening metathesis polymerization (ROMP), ROMP and hydrogenation combination, by free radical or kation carry out be polymerized, use the polymerization of cationic palladium polymerization initiator, all known polymerization of polymerization etc. of (such as, the polymerization initiator of nickel or other transition metal) obtains to use polymerization initiator in addition.

On the other hand, clad 11 and clad 12 form respectively and are positioned at the bottom of core 14 and the covering portion on top.By such formation, the guide path that core 14 surrounds as its periphery portion of being wrapped by plays a role.

The average thickness of preferred clad 11,12 is 0.1 ~ 1.5 times of the average thickness of sandwich layer 13, be more preferably 0.3 ~ 1.25 times, specifically, to the average thickness of clad 11,12, there is no particular limitation, but be usually preferably 1 ~ 200 μm respectively, be more preferably 5 ~ 100 μm, more preferably 10 ~ 60 μm.Thus, prevent the unnecessary maximization (thick-film) of optical waveguide 10, effectively can play the function as clad simultaneously.

In addition, as the constituent material of clad 11 and 12, such as, can use the material identical with the constituent material of above-mentioned sandwich layer 13, but particularly preferably norbornene polymer.

In the present embodiment, between the constituent material and the constituent material of clad 11,12 of sandwich layer 13, consider refringence between the two, different materials can be selected aptly.Therefore, select to produce the material of the enough refringences needed for the total reflection reliably carrying out light on the border of sandwich layer 13 and clad 11,12.Thus, the thickness direction of optical waveguide 10 can obtain sufficient refringence, and light can be suppressed to escape to clad 11,12 from core 14.Its result, can suppress to transmit the decay at the light of core 14.

In addition, from the viewpoint of suppressing optical attenuation, between preferred sandwich layer 13 and clad 11,12, there is high adhesion.Therefore, for the constituent material of clad 11,12, as long as meet refractive index lower than the refractive index of the constituent material of sandwich layer 13 and the condition high with the adaptation of the constituent material of sandwich layer 13, can be arbitrary constituent material.

Such as, as the norbornene polymer had compared with low-refraction, preferably comprise the polymkeric substance that end has the repetitive of the substituent norborene containing epoxy construction.While this norbornene polymer has refractive index low especially, adaptation is good.

In addition, preferred norbornene polymer contains the repetitive of alkyl norbomene.The flexibility of the norbornene polymer of the repetitive containing alkyl norbomene is high, therefore by using this norbornene polymer, can give high flexibility (pliability) to optical waveguide 10.

As the alkyl that alkyl norbomene repetitive has, such as, propyl group, butyl, amyl group, hexyl, heptyl, octyl group, nonyl, decyl etc. can be enumerated, particularly preferably hexyl.In addition, these alkyl both can be any one in straight-chain or branched.

By the repetitive containing hexyl norborene, the rising of norbornene polymer overall refractive index can be prevented.In addition, there is the norbornene polymer of hexyl norborene repetitive, excellent to the light transmission of above-mentioned wavelength region may (wavelength region may particularly near 850nm), therefore preferably.

In addition, clad 11, side covering portion 15 and the constituent material of clad 12 can be the material of identical (identical type), also can be different materials, but preferably these constituent materials are the material that refractive index is approximate.

This optical waveguide of the present invention 10, can according to optical characteristics of core 14 material etc. and some is different, and to this, there is no particular limitation, and such as, this optical waveguide is preferably applicable in the data communication of the light of use 600 ~ 1550nm wavelength region may.

At this, as mentioned above, side covering portion 15 is divided into multiple high-refractive-index regions 151 and refractive index lower than the region of low refractive index 152 of this high-refractive-index regions 151.

Optical waveguide of the present invention, is characterized in that, the part in covering portion contains this high-refractive-index regions.

Below, high-refractive-index regions 151 and region of low refractive index 152 are described in detail.

As shown in Figure 2, in each side covering portion 15, region of low refractive index 152 is arranged to contact with each core 14.On the other hand, as shown in Figure 2, high-refractive-index regions 151 is arranged to directly not contact with each core 14.That is, the state inserting region of low refractive index 152 between high-refractive-index regions 151 and each core 14 is become.

In addition, multiple high-refractive-index regions 151 is arranged to: when overlooking, this high-refractive-index regions is slat respectively and fitly arranges in the mode that axis is parallel to each other.In addition, when overlooking, each high-refractive-index regions 151 shown in Fig. 2 is parallelogram respectively.In addition, in each side covering portion 15, these multiple high-refractive-index regions 151 clip each core 14 and are fitly arranged in both sides.In addition, each high-refractive-index regions 151 shown in Fig. 2 is in elongated parallelogram, and the length on preferred long limit is 2 ~ 50 times of minor face, more preferably 5 ~ 30 times.

In addition, as shown in Figure 2, these are the mode that the high-refractive-index regions 151 of slat is arranged to cross in the direction of the width each side covering portion 15.Its result, by each high-refractive-index regions 151, will inevitably reliably can play the function of each high-refractive-index regions 151 described later by the light of each side covering portion 15.

This each high-refractive-index regions 151 in slat is arranged to: the axis of each high-refractive-index regions respectively relative to the vertical line of core 14 axis to the back sweep of the working direction of the light by core 14.Arrange based on so tilting, by the light of each high-refractive-index regions 151, when incident from region of low refractive index 152 to high-refractive-index regions 151 and when from high-refractive-index regions 151 to region of low refractive index 152 outgoing, according to both refringences, inevitable to reflect away from the mode of core 14.Its result, can make by the light of side covering portion 15 away from core 14, and in the exiting side end face 10b of optical waveguide 10, the standoff distance between the Exit positions of the light come through core 14 transmission and the Exit positions transmitting the light come through side covering portion 15 can be guaranteed fully.

Now, as shown in Figure 2, can according to the width etc. of the refringence between high-refractive-index regions 151 and region of low refractive index 152 and side covering portion 15, set angle (pitch angle of the high-refractive-index regions 151) θ formed with the axis of each high-refractive-index regions 151 in slat by the vertical line of core 14 axis rightly, to make inevitable by the light of side covering portion 15 and reliably to reflect.

Specifically, the tiltangleθ of preferred high-refractive-index regions 151 is 10 ~ 85 °, is more preferably 20 ~ 70 °.By being set at pitch angle within above-mentioned scope, the light spilt from core 14, reliably to reflect away from the mode of core 14, thus in the exiting side end face 10b of optical waveguide 10, can isolate flashlight and stray light.Its result, can improve the S/N ratio as carrier wave more reliably.

In addition, the standoff distance between each high-refractive-index regions 151, also suitably can be arranged according to the width etc. of the refringence between high-refractive-index regions 151 and region of low refractive index 152 or side covering portion 15.

And the width of each high-refractive-index regions 151 also suitably can be arranged according to same way, but as an example, preferred above-mentioned width is 1 ~ 30 μm, more preferably 3 ~ 20 μm.

In addition, for the shape of high-refractive-index regions 151, as long as in slat (elongated shape), just there is no particular limitation, except the quadrangle such as trapezoidal, rectangle, rhombus, can also be the polygon as pentagram, sexangle etc.; The circle of ellipse, Long Circle etc.

At this, optical waveguide is in the past described.

Figure 17 is the vertical view of the sandwich layer only representing optical waveguide 90 in the past.

Sandwich layer 93 shown in Figure 17 has and alternately configures parallel and two cores 94 of arranging and the formation of three side covering portion 95.In addition, use up to irradiate communication to such sandwich layer 93, with each core 94 accordingly, light-emitting component 97 is set respectively at the light incident side of optical waveguide 90, arranges in exiting side and be used for the photo detector 98 of Received signal strength light.

In such sandwich layer 93, the refractive index due to air is less than the refractive index of side covering portion 95, therefore, side covering portion 95 with the interface of its space outerpace (air) produces the total reflection of light.Therefore, the light inciding side covering portion 95 based on any reason transmits while repeating to be totally reflected in side covering portion 95 with the interface of air, and is penetrated by exiting side end face 90b.Thus, the part through the light of side covering portion 95 transmission arrives photo detector 98 together with the flashlight transmitted through core 94.Its result, transmits through side covering portion 95 stray light that the light come becomes flashlight, causes the S/N ratio as carrier wave to decline.Therefore, in optical waveguide 90 in the past, improve S/N ratio as carrier wave and the quality improving optical communication becomes the technical task that will solve.

But, incide one of reason of side covering portion 95 as light, the mutually unaccommodated situation of opening number of the optical axis of optical waveguide 90 and the skew of the optical axis of light-emitting component 97 and optical waveguide 90 and light-emitting component 97 can be enumerated.Usually preferably the optical axis of core 94 and opening number consistent with the optical axis of light-emitting component 97 mates mutually, core 94 is incided to enable all light of generation self-emission device 97, but when these conditions are insufficient, a part of light can incide the side covering portion 95 of the light incident side end face 90a of optical waveguide 90.And, because the xsect of core 94 is extremely small, therefore, when configuring light-emitting component 97, reach that optical axis is consistent and the state realizing opening number coupling is extremely difficult.

And, with in the mutual unaccommodated situation of opening number of photo detector 98 when the optical axis of optical waveguide 90 and the optical axis of photo detector 98 offset from each other and in optical waveguide 90, transmit through side covering portion 95 light come and also can arrive photo detector 98, cause the S/N ratio as carrier wave to decline.

In addition, incide the other reasons of side covering portion 95 as light, light light in the way of optical waveguide 90 can be enumerated and escape to the situation of side covering portion 95 from core 94.Spill from the optical transport of core 94 in the covering portion of side, and make S/N as carrier wave than declining as mentioned above.

Therefore, in the present invention, as described above, by arrangement in a part for side covering portion 15, the as above multiple high-refractive-index regions 151 of refractive index higher than other regions (region of low refractive index 152) are set, thus, at the light that the side covering portion 15 of optical waveguide 10 is transmitted when by high-refractive-index regions 151, can to reflect away from the mode of core 14.Therefore, in the exiting side end face 10b of optical waveguide 10, the standoff distance between the Exit positions of the light transmitted by core 14 and the Exit positions being transmitted the light come by side covering portion 15 fully can be guaranteed.Thus, even if when light incides side covering portion 15, also high-refractive-index regions 151 can be passed through, to make this light reflect away from the mode of core 14.

At this, in Fig. 3, illustrate the path of the light by the optical waveguide shown in Fig. 2.According to the present invention, as shown in Figure 3, be induced as away from core 14 by the light (representing with dotted arrow) of side covering portion 15, can not affect thus and penetrate and by the light (representing with solid arrow) of core 14 from light-emitting component 17.Its result, in exiting side end face 10b, can be separated with the Exit positions 151L transmitting the stray light come through high-refractive-index regions 151 the Exit positions 14L transmitting the flashlight come through core 14 fully.And, this stray light can be suppressed receive by photo detector 18, the decline of the S/N ratio as carrier wave can be prevented thus.

In addition, as shown in Figure 2, high-refractive-index regions 151 and core 14 are in the state separated.If high-refractive-index regions 151 contacts with core 14, then exist through core 14 transmit light likely from this element branches to high-refractive-index regions 151 side, but, because high-refractive-index regions 151 and core 14 are in the state separated, therefore, it is possible to prevent the optical branch that transmits through core 14 to the phenomenon of high-refractive-index regions 151 side.

For such high-refractive-index regions 151, as long as its refractive index is higher than other regions of side covering portion 15, namely higher than region of low refractive index 152, but preferred index difference is more than 0.5%, is more preferably more than 0.8%.In addition, to higher limit, there is no particular limitation, but be preferably 5.5%.By arranging refringence so fully between high-refractive-index regions 151 and region of low refractive index 152, total reflection can be produced at the interface of high-refractive-index regions 151 and region of low refractive index 152.Its result, escapes to the phenomenon of region of low refractive index 152 with more reliably preventing the non-original idea of light transmitted through high-refractive-index regions 151.

In addition, preferred high-refractive-index regions 151 does not spill in light incident side end face 10a.Thus, light can not be directly incident in high-refractive-index regions 151, and light can be suppressed to transmit in high-refractive-index regions 151.Its result, reliably can play the function of high-refractive-index regions 151 as above.

On the other hand, preferred high-refractive-index regions 151 is not exposed to the exiting side end face 10b of optical waveguide 10 yet.If high-refractive-index regions 151 is exposed to exiting side end face 10b, then the light with relative high strength likely penetrates from this part, if do not exposed, high-refractive-index regions 151 can reliably play the function that should play, and reliably can improve S/N ratio.

In addition, as shown in Figure 2, preferred multiple high-refractive-index regions 151 in optical waveguide 10 from light incident side end face 10a to exiting side end face 10b, be arranged to be distributed on whole length direction.Thus, can not only make to incide the light of side covering portion 15 away from core 14 from light incident side end face 10a, and can reliably make to escape to the light of side covering portion 15 away from core 14 from core 14 in the way of optical waveguide 10.

In addition, as shown in Figure 2, when having multiple core 14,14(hyperchannel) time, if be provided with above-mentioned high-refractive-index regions 151, then can effectively suppress stray light the phenomenon that receives by the photo detector that corresponds respectively to beyond the photo detector of each core 14,14, namely can effectively suppress bleed (crosstalk) of the flashlight from other passages.

Now, be arranged on the high-refractive-index regions 151 in the side covering portion 15 between adjacent core 14,14, to be positioned at nearest core 15 for benchmark and regulation vergence direction.Therefore, as shown in Figure 2, be configured at each high-refractive-index regions 151 between parallel core 14,14, the arrangement of V shape will inevitably be become.

At this, Fig. 9 represents another configuration example of the first embodiment shown in Fig. 2.

In optical waveguide 10 shown in Fig. 9, except the plan view shape difference of the high-refractive-index regions in slat, other are identical with Fig. 2.That is, when overlooking, the side covering portion 15 shown in Fig. 9 has the multiple high-refractive-index regions 151 ' in slat, but when overlooking, the plurality of high-refractive-index regions 151 ' is in elongated triangle.

In addition, identically with the high-refractive-index regions 151 shown in Fig. 2, this high-refractive-index regions 151 ' is arranged to the vertical line of its axis relative to core 14 axis to the back sweep of the working direction of the light by core 14.

And, each high-refractive-index regions 151 ' in from core 14 side more away from the shape that increases gradually of its cross-sectional area.Each high-refractive-index regions 151 ' of this shape, can more effectively decay by the light of side covering portion 15.Its result, can improve the S/N ratio as carrier wave further.

In Fig. 9, be in multiple high-refractive-index regions 151 ' of elongated triangular when overlooking, the interior angle being positioned at core 14 side is acute angle, and its angle is less than other interior angles.Specifically, preferably this interior angle is 3 ~ 30 °, is more preferably 5 ~ 20 °.

In addition, now opposite with the interior angle the being positioned at core 14 side length of side is shorter than other two length of sides.Specifically, long relative to the minor face in other both sides, the length of side opposite with the interior angle being positioned at core 14 side is preferably 0.02 ~ 0.5 times, is more preferably 0.03 ~ 0.2 times.

In addition, Figure 10 represents another configuration example of the first embodiment shown in Fig. 2.

Optical waveguide 10 shown in Figure 10, except the plan view shape difference of the high-refractive-index regions in slat, other are identical with Fig. 2.Namely, when overlooking, the side covering portion 15 shown in Figure 10 has the multiple high-refractive-index regions 151 in slat ", when overlooking; the plurality of high-refractive-index regions 151, " in elongated rectangle, and the extended line being configured to its axis is almost vertical relative to the axis of core 14.

In addition, " in elongated rectangle, the length on preferred long limit is 2 ~ 50 times of minor face to each high-refractive-index regions 151 shown in Figure 10, is more preferably 5 ~ 30 times.

Multiple each high-refractive-index regions 151 like this " can make transmission at the light of side covering portion 15 to carry out reflecting or scattering away from the mode of core 14, effectively therefore, it is possible to more effectively decay by the light of side covering portion 15.Its result, can further improve the S/N ratio as carrier wave.

These high-refractive-index regions 151 ' and high-refractive-index regions 151 " have the function identical with above-mentioned each high-refractive-index regions 151.

Below, an example of the manufacture method of optical waveguide 10 is described.

Optical waveguide 10 is by making clad 11(ground floor respectively), the sandwich layer 13(second layer) and clad 12(third layer), and by they laminations and manufacturing in addition.

In this manufacture method, must make the mutually different position of refractive index physically and contact optically.Specifically, region of low refractive index 152 and each clad 11,12 must positively be bonded on core 14, can not have gap.In addition, also must positively bond together between high-refractive-index regions 151, region of low refractive index 152 and each clad 11,12.

As the manufacture method that this is concrete, as long as the method for core 14, high-refractive-index regions 151, region of low refractive index 152 etc. can be formed with regard to there is no particular limitation in same layer (second layer), such as, photobleaching (photobleaching) method, photoetching process, directly exposure method, nano-imprint method and monomer diffusion method etc. can be enumerated.

At this, representatively, the manufacture method of the optical waveguide 10 adopting monomer diffusion method is described.

Fig. 4 ~ Fig. 8 is respectively the schematic section of the manufacture method operation example representing the optical waveguide 10 shown in Fig. 1.Wherein, Fig. 5,6,8 is sectional views of the A-A line of Fig. 2.

[1] first, supporting substrates 161 is formed layer 110(with reference to Fig. 4).

Layer 110 is by coating sandwich layer formation material (varnish) 100 and the method for its harden (solidification) is formed.

Specifically, layer 100 is formed by following manner: on supporting substrates 161, be coated with sandwich layer formation material 100 and after forming aqueous tunicle, this supporting substrates 161 is placed on the horizontal desk of ventilation, with make the uneven part on aqueous tunicle surface reach smooth while, evaporating solvent (desolventizing), forms layer 110 thus.

When adopting rubbing method to form layer 110, such as, can enumerate and scrape the skill in using a kitchen knife in cookery, spin-coating method, dip coating, desktop rubbing method (テ ー Block Le コ ー ト method), spraying process, semar technique (Applicator), curtain coating processes (curtaincoat), die coating method (diecoating) etc., but be not limited thereto.

As supporting substrates 161, such as, can use silicon substrate, silicon dioxide substrate, glass substrate, quartz base plate, polyethylene terephthalate (PET) film etc.

Sandwich layer formation material 100 containing by polymkeric substance 115 and adjuvant 120(at least containing monomer and catalyzer) the developability material that forms, be the irradiation by active radioactive ray and heating, in polymkeric substance 115, produce the material of monomer reaction.

And in obtained layer 110, polymkeric substance (matrix) 115 is in fact all with evenly and be irregularly assigned with, and adjuvant 120 is in fact all with evenly and be irregularly dispersed in polymkeric substance 115.Thus, adjuvant 120 in fact evenly and at random disperse in layer 110.

The average thickness of such layer 110 suitably can set according to the thickness of the sandwich layer 13 that will be formed, and has no particular limits, but preferably 5 ~ 200 μm, more preferably 10 ~ 100 μm, preferably 15 ~ 65 μm further.

As polymkeric substance 115, the transparency enough high (water white transparency) can be used and with monomer described later, there is the material of intermiscibility, and then, preferably use monomer as hereinafter described wherein can react (polyreaction or cross-linking reaction) and after monomer polymerization, also have the material of the transparency fully.

At this, " having intermiscibility " refers at least after mix monomer, in sandwich layer formation with in material 100 or in layer 110, can not occur to be separated with polymkeric substance 115.

As such polymkeric substance 115, the constituent material of above-mentioned sandwich layer 13 can be enumerated.

In addition, when using norbornene polymer as polymkeric substance 115, because this polymkeric substance has high hydrophobicity, therefore can obtain and be difficult to because water suction causes the sandwich layer 13 of change in size.

In addition, as norbornene polymer, can for have independent repetitive material (homopolymer), have in the material (multipolymer) of two or more norborene class repetitive any one.

Wherein, as an example of multipolymer, preferential use has the compound of the repetitive shown in following formula (1).

[in formula, m represents the integer of 1 ~ 4, and n represents the integer of 1 ~ 9.]

Wherein, as multipolymer kind, can be two unit of above-mentioned formula (1) arrange with random order (random) material, the material be alternately arranged, each unit respectively form arbitrarily such as (block-wise) material of arranging in a fixed manner material.

At this, when using above-mentioned norbornene polymer as polymkeric substance 115, as an example of adjuvant 120, preferably containing Norbornene derivative, promotor (the first material) and catalyst precursor (the second material).

Norbornene derivative is by active radiation exposure described later, carry out reacting and forming reactions thing in the irradiation area of active radioactive ray, by the existence of this reactant, make in the non-irradiated regions of the irradiation area of layer 110 and active radioactive ray, produce the compound of refringence.

At this, as this reactant, Norbornene derivative can be enumerated and be polymerized in polymkeric substance (matrix) 115 and the polymkeric substance (condensate) formed, polymkeric substance 115 be cross-linked to each other and the cross-linked structure formed and to be polymerized with polymkeric substance 115 and from least one the branched structure (branched polymer or side chain (side base)) of polymkeric substance 115 branch.

At this, in layer 110, when wishing the refractive index height of irradiation area, by have compared with low-refraction polymkeric substance 115 and relative to this polymkeric substance 115 have high index of refraction Norbornene derivative combination and use, when wishing that the refractive index of irradiation area is low, will there is the polymkeric substance 115 of high index and relative to this polymkeric substance 115, there is the Norbornene derivative combination of low-refraction and use.

In addition, this said refractive index " height " or " low ", not the absolute value meaning refractive index, but mean material relativeness each other.

By the reaction (generation of reactant) of Norbornene derivative, when the refractive index of irradiation area reduces in layer 110, this part becomes side covering portion 15, and when the refractive index of irradiation area rises, this part becomes core 14.

Catalyst precursor (the second material) is the material that can cause above-mentioned monomer reaction (polyreaction, cross-linking reaction), be by described later, by the irradiation of active radioactive ray by the effect of promotor (the first material) activated, change the material of activation temperature.

As this catalyst precursor (procatalyst), as long as the irradiation along with active radioactive ray changes the material of activation temperature (rise or decline), any compound can be used, but particularly preferably along with the material that its activation temperature of irradiation of active radioactive ray reduces.Thus, the heating by lower temperature forms sandwich layer 13(optical waveguide 10), can prevent from making because applying unnecessary heating to other layers the phenomenon that the characteristic of optical waveguide 10 (optical transmission performance) reduces.

As such catalyst precursor, preferably use the material of at least one (as major component) in the compound represented containing following formula (Ia) and (Ib).

（E（R) ₃） ₂Pd（Q） ₂···（Ia）

[（E（R) ₃） _aPd（Q）（LB） _b] _p[WCA] _r···（Ib）

[in formula Ia, Ib, E (R) ₃represent the neutral electron donor ligand of the 15th race respectively; E represents the element being selected from periodic table the 15th race; R represents hydrogen atom (or the one in its isotope) or the position containing alkyl; Q represents the anion ligand be selected from carboxylate, carbothioic acid ester and dithiocarboxylic esters.In addition, in formula Ib, LB represents lewis base; WCA represents Weakly coordinating anions; A represents the integer of 1 ~ 3, and b represents the integer of 0 ~ 2, a and b's and be 1 ~ 3; P and r represents the number getting charge balance between palladium kation and Weakly coordinating anions.]

As the representational catalyst precursor that formula Ia represents, Pd (OAc) can be enumerated ₂(P (i-Pr) ₃) ₂, Pd (OAc) ₂(P (Cy) ₃) ₂, Pd (O ₂cCMe ₃) ₂(P (Cy _{) 3}) ₂, Pd (OAc) ₂(P (Cp) ₃) ₂, Pd (O ₂cCF ₃) ₂(P (Cy) ₃) ₂, Pd (O ₂cC ₆h ₅) ₃(P (Cy _{) 3}) ₂, but be not limited thereto.At this, Cp representative ring amyl group (cyclopentyl), Cy representative ring hexyl.

In addition, as the catalyst precursor that formula Ib represents, preferred p and r is selected from the compound in the integer of 1 and 2 respectively.

As the representational catalyst precursor that formula Ib represents, Pd (OAc) can be enumerated ₂(P (Cy _{) 3}) ₂.At this, Cy representative ring hexyl, Ac represents acetyl group.

These catalyst precursor can make monomer effectively carry out reacting (when for Norbornene derivative, effectively carrying out polyreaction or cross-linking reaction etc. by polyaddition reaction).

Promotor (the first material) is activated by the irradiation of active radioactive ray, thus changes the material of the activation temperature (temperature of trigger monomer reaction) of above-mentioned catalyst precursor (procatalyst).

As this promotor (cocatalyst), as long as by its molecule structure change of irradiation (reaction or decomposition) of activity radioactive by the compound activated, arbitrary compound can be used, but preferably use the promotor containing (as major component) following compound (light trigger): this compound (light trigger) is, decompose by the irradiation of the active radioactive ray of specific wavelength, produce proton, the kation (cation) of other kations etc., and the compound of Weakly coordinating anions (WCA) of disengaging base of catalyst precursor can be replaced.

As Weakly coordinating anions, such as, four (pentafluorophenyl group) borate ion (FABA can be enumerated ^-), hexafluoro-antimonic acid ion (SbF ₆ ^-) etc.

As this promotor (photoacid generator or Photobase generator), such as, can enumerate: four (pentafluorophenyl group) borate, hexafluoro antimonate, in addition, four (pentafluorophenyl group) gallate, aluminate class, metaantimmonic acid salt, other borate family, gallic acid salt, carborane class, halocarbon boranes etc. are also had.

In addition, sandwich layer is formed with in material (varnish) 100, can add sensitizer as required.

And, can also antioxidant be added in sandwich layer formation material 100.Thus, the generation of undesirable free free radical and the autoxidation of polymkeric substance 115 can be prevented.Its result, can improve obtained sandwich layer 13(optical waveguide 10) characteristic.

Sandwich layer formation material 100 as above is utilized to form layer 110.

Now, layer 110 has first refractive rate.This first refractive rate depends on dispersed (distribution) polymkeric substance 115 in layer 110 and the effect of monomer.

In addition, in the explanation of above-mentioned adjuvant 120, although be illustrated the situation that monomer is Norbornene derivative, but as the monomer beyond this Norbornene derivative, as long as have the compound at polymerizable position, acrylic acid (methacrylic acid) class monomer, epoxy monomer, styrene monomer etc. can be enumerated, the one in these monomers can be used or combinationally use two kinds.

In addition, for the catalyzer in adjuvant 120, can select aptly according to the kind of monomer, such as, when for acrylic monomer or epoxy monomer, the interpolation of catalyst precursor (the second material) can be omitted.

[2] then, prepare the mask (masking) 135 being formed with opening (window) 1351, by this mask 135, irradiate active radioactive ray (active-energy light) 130(with reference to Fig. 5 to layer 110).

Below, use refractive index lower than the monomer of polymkeric substance 115 as monomer, and for sandwich layer formation material 100, along with the irradiation of activity radioactive 130, the situation that the refractive index of irradiation area 125 reduces is that example is described.

That is, in this example, the irradiation area 125 of activity radioactive 130 becomes the region of low refractive index 152 in side covering portion 15.

Therefore, in this example, mask 135 is formed with the opening (window) 1351 identical with the pattern of the region of low refractive index 152 that will be formed.This opening 1351 forms the through portion through irradiated active radioactive ray 130.

Mask 135 can be the mask (mask of such as tabular) being pre-formed (separately formed), also can be such as by mask that gas phase membrane formation process or rubbing method are formed on layer 110.

With regard to used active radioactive ray 130, as long as the radioactive ray of photochemical reaction (change) can be produced to promotor, such as, visible ray, ultraviolet light, infrared light, laser can be enumerated, in addition, electron ray, x-ray etc. can also be used.

When active radioactive ray 130 being radiated at layer 110 by mask 135, be present in the promotor (the first material: co-catalyst) in the irradiation area 125 that irradiated by active radioactive ray 130, reacted (combination) by the effect of active radioactive ray 130 or decompose, thus free (generation) kation (proton or other kations) and Weakly coordinating anions (WCA).

And these kations or Weakly coordinating anions make the molecular structure of the catalyst precursor (the second material: procatalyst) be present in irradiation area 125 change (decomposition), are changed into active sneak condition (potential activated state).

As active radioactive ray 130, when using light as high in directive property such as laser, the use of mask 135 also can be omitted.

[3] then, apply to heat (first heats) to layer 110.

Thus, in irradiation area 125, the catalyst precursor being in active sneak condition is activated (becoming activated state), causes monomer reaction (polyreaction or cross-linking reaction).

And along with the carrying out of monomer reaction, the monomer concentration in irradiation area 125 reduces gradually.Thus, produce the concentration difference of monomer between irradiation area 125 and non-irradiated regions 140, in order to eliminate this concentration difference, monomer spreads (monomer spreads, monomerdiffusion) from non-irradiated regions 140 and concentrates on irradiation area 125.

Its result, in irradiation area 125, monomer and its reactant (condensate, cross-linked structure or branched structure) increase, and the structure from monomer strengthens the impact of the refractive index in this region, and refractive index drops to second refractive index lower than first refractive rate.In addition, as the condensate of monomer, mainly generate addition (being total to) polymkeric substance.

On the other hand, in non-irradiated regions 140, because monomer makes amount of monomer reduce from this regional diffusion to irradiation area 125, therefore, polymkeric substance 115 strengthens the impact of this areas diffract rate, and refractive index rises to the third reflect rate higher than first refractive rate.

So, between irradiation area 125 and non-irradiated regions 140, produce refringence (the second refractive index < third reflect rate), form core 14, high-refractive-index regions 151(non-irradiated regions 140 thus) and region of low refractive index 152(irradiation area 125) (with reference to Fig. 6).

[4] then, the second heating is carried out to layer 110.

Thus, make the catalyst precursor direct activation (making it be in active state) residuing in non-irradiated regions 140 and/or irradiation area 125, or make catalyst precursor activation (making it be in active state) residuing in non-irradiated regions 140 and/or irradiation area 125 along with the activation of promotor, thus the monomer residuing in each region 125,140 is reacted.

So, by making the monomer residuing in each region 125,140 react, the stabilization of obtained core 14, high-refractive-index regions 151 and region of low refractive index 152 can be realized.

[5] following, the 3rd heating is carried out to layer 110.

Thereby, it is possible to reduce the internal stress produced at obtained sandwich layer 13, realize the further stabilization of core 14, high-refractive-index regions 151 and region of low refractive index 152.

Through above operation, obtain the sandwich layer 13(second layer).

Wherein, under state such as before enforcement second is heated or the 3rd heats, core 14, the situation having obtained sufficient refringence between high-refractive-index regions 151 and region of low refractive index 152 are inferior, also can omit this operation [5] or above-mentioned operation [4].

[6] then, supporting substrates 162 forms clad 11(12) (with reference to Fig. 7).

As clad 11(12) formation method, can adopt coating containing the varnish (clad is formationed material) carrying out of clad material harden (solidification) method and be coated with and there is indurative monomer composition and any one method in making the method for its harden (solidification) etc.

Rubbing method is utilized to form clad 11(12) time, such as, can enumerate and scrape the skill in using a kitchen knife in cookery, spin-coating method, dip coating, desktop rubbing method, spraying process, semar technique (applicator), curtain coating processes, die coating method etc.

As supporting substrates 162, the substrate identical with supporting substrates 161 can be used.

As mentioned above, supporting substrates 162 forms clad 11(12).

[7] following, peel off sandwich layer 13 from supporting substrates 161, and by being formed with clad 11(ground floor) supporting substrates 162 and be formed with clad 12(third layer) supporting substrates 162 clamp this sandwich layer 13(with reference to Fig. 8).

Then, as shown by the arrows in fig. 8, from be formed clad 12 supporting substrates 162 above apply pressure, crimping clad 11,12 and sandwich layer 13.

Thus, clad 11,12(ground floor and third layer) and the sandwich layer 13(second layer) engage form integrated.

In addition, preferably this crimping operation carries out under heating.Heating-up temperature can be carried out suitable selection according to the constituent material etc. of clad 11,12 and sandwich layer 13 and is usually preferably 80 ~ 200 DEG C, is more preferably 120 ~ 180 DEG C.

Next, peel off respectively from clad 11,12 and remove supporting substrates 162.Thus, optical waveguide 10(optical waveguide of the present invention is obtained).

By said method, core 14 and high-refractive-index regions 151 can be formed in same manufacturing process simultaneously.Therefore, without the need to increasing process number in manufacture method in the past, can effectively produce high-refractive-index regions 151 and region of low refractive index 152 in side covering portion 15.

In addition, the core 14 so formed and high-refractive-index regions 151 are made up of the material of identical type.Therefore, both thermal expansivity are identical, with compared with the situation that different materials is formed, can reduce the unfavorable condition of the distortion, splitting etc. of the optical waveguide 10 produced with temperature variation.

To sum up, the manufacture method of the optical waveguide 10 adopting monomer diffusion method is illustrated, but as mentioned above, in the manufacture method of optical waveguide 10, also can uses additive method.

Wherein, in Photobleaching, such as can use the sandwich layer formation material containing release agent (material) and polymkeric substance, wherein, described release agent (material) activates by the irradiation of active radioactive ray; Described polymkeric substance have main chain and from this main chain branch and by activation release agent effect molecular structure at least partially can from main chain depart from detachment group (detachment side base).After this sandwich layer formation material filming is stratiform, by ultraviolet isoreactivity radiation exposure in the part of this layer, detachment group departs from (cut-out) thus, and the refractive index in this region changes (rise or decline).Such as, when when the disengaging along with detachment group, refractive index declines, then the irradiation area of active radioactive ray becomes region of low refractive index 152, and region in addition becomes core 14 or high-refractive-index regions 151.After so forming sandwich layer 13, as mentioned above, at the two sides joining clad layer 11,12 of sandwich layer 13.

On the other hand, in photolithography, such as, the layer of the core formation material of high index of refraction is formed on clad 11, and then, on this layer, the resist film of the shape corresponding with core 14 and high-refractive-index regions 151 is formed by photoetching technique.Then, using this resist film as mask, the layer of etching core formation material.Thus, core 14 and high-refractive-index regions 151 can be obtained.Then, to cover the mode of core 14 and high-refractive-index regions 151, form the film of the relatively low covering portion formation material of refractive index, thus, fill the gap between core 14 and high-refractive-index regions 151 by covering portion formation material, obtain region of low refractive index 152.In addition, further, supply covering portion formation material in the mode covering these regions (core 14, high-refractive-index regions 151 and low index ellipsoid 152), obtain clad 12 thus.

< second embodiment >

Next, the second embodiment of optical waveguide of the present invention is described.

Figure 11 is the vertical view of the sandwich layer of the second embodiment only representing optical waveguide of the present invention.

Below, the optical waveguide of present embodiment is described, but is mainly described centered by the difference of the optical waveguide with above-mentioned first embodiment, this explanation is omitted for identical part.

In the optical waveguide of present embodiment, except high-refractive-index regions and region of low refractive index overlook pattern different except, identical with above-mentioned first embodiment.

For the side covering portion 15 shown in Figure 11, there are when overlooking multiple high-refractive-index regions 153 in pelletized form.

The plurality of high-refractive-index regions 153 identically with the high-refractive-index regions 151 illustrated in above-mentioned first embodiment, be the region of refractive index higher than region of low refractive index 152, and be fitly arranged in both sides in the mode clamping core 14.

In addition, each high-refractive-index regions 153 is separate, and is arranged to directly not contact with each core 14.That is, the state inserting region of low refractive index 152 between high-refractive-index regions 153 and each core 14 is respectively become.

Such high-refractive-index regions 153, as long as long as its refractive index is higher than other regions of side covering portion 15, namely higher than region of low refractive index 152, but preferably its refringence is more than 0.5%, is more preferably more than 0.8%.In addition, can set especially higher limit, but be preferably 5.5%.By the refringence so fully of design between high-refractive-index regions 153 and region of low refractive index 152, total reflection reliably can be produced in the interface between high-refractive-index regions 153 and region of low refractive index 152.Its result, can more reliably prevent the light transmitted in high-refractive-index regions 153 from escaping to the situation of region of low refractive index 152 when non-original idea.

In addition, preferred high-refractive-index regions 153 is not exposed in light incident side end face 10a.Thus, light can not be directly incident in high-refractive-index regions 153, can suppress the phenomenon that light transmits in high-refractive-index regions 153.Its result, reliably can play the function of above-mentioned high-refractive-index regions 153.

On the other hand, preferred high-refractive-index regions 153 is not exposed in the exiting side end face 10b of optical waveguide 10 yet.If high-refractive-index regions 153 is exposed to exiting side end face 10b, then the light of high strength likely penetrates from this part relatively, if but were not exposed to exiting side end face 10b, then reliably could play the intrinsic function of high-refractive-index regions 153, reliably can improve S/N ratio.

In addition, as shown in figure 11, preferred multiple high-refractive-index regions 153 in optical waveguide 10 from light incident side end face 10a to exiting side end face 10b, be arranged to be distributed on whole length direction.Thus, can not only make to incide the light of side covering portion 15 away from core 14 from light incident side end face 10a, and, also can reliably make to escape to the light of side covering portion 15 away from core 14 from core 14 in the way of optical waveguide 10.

In addition, as shown in figure 11, when having multiple core 14,14(many passages) time, if be provided with high-refractive-index regions 153 as above, then effectively can suppress the phenomenon that stray light is received by the photo detector corresponded respectively to beyond the photo detector of each core 14,14, bleed (crosstalk) that namely effectively can suppress the flashlight from other passages.

In the optical waveguide 10 of such present embodiment, the way of transmitting from the light of light incident side end face 10a incidence to exiting side end face 10b, when escaping to side covering portion 15(region of low refractive index 152 by core 14) light arrive high-refractive-index regions 153 time, carry out random scattering in this region.Thus, the light escaping to side covering portion 15 from core 14 produces decay arriving the forward direction wide region diffusion of exiting side end face 10b.Its result, in exiting side end face 10b, the light intensity of the stray light of covering portion 15 injection from the side can reduce, and can improve the S/N ratio as carrier wave thus.

For the plan view shape of high-refractive-index regions 153 in pelletized form, there is no particular limitation, such as, can enumerate the circle of positive circle, ellipse, Long Circle etc.; The polygon of triangle, quadrangle, sexangle, octagon, star etc.; Semicircle, fan-shaped etc.

In addition, as shown in figure 11, the profile of preferred high-refractive-index regions 153 have concavo-convex.Thus, the profile of high-refractive-index regions 153 can make reception spill has scrambling from the mask of the light of core 14, reliably can carry out the diffuse reflection of light.

In addition, the mean grain size of preferred each high-refractive-index regions 153 is 10 ~ 500 μm, is more preferably 20 ~ 300 μm.By making the mean grain size of each high-refractive-index regions 153 be located within above-mentioned scope, the probability of the scattered light of each high-refractive-index regions 153 fully can be improved.

In addition, the refringence between preferred each high-refractive-index regions 153 and region of low refractive index 152 is more than 0.5%, is more preferably more than 0.8%.In addition, for higher limit without the need to setting especially, but be preferably 5.5%.

At this, Figure 12 represents other configuration examples of the second embodiment shown in Figure 11.

In the optical waveguide 10 shown in Figure 12, except the configuration pattern difference of multiple high-refractive-index regions 153, other parts are identical with Figure 11.That is, the multiple high-refractive-index regions 153 shown in Figure 11 configure in the mode of proper alignment, but multiple high-refractive-index regions 153 are as shown in figure 12 configured in the mode of irregular (at random).Thus, when the light by side covering portion 15, in high-refractive-index regions 153, scattering occurs, the phenomenon mutually disturbed at the light of multiple high-refractive-index regions 153 scattering can be suppressed.Its result, can prevent the phenomenon that the light intensity of the stray light because disturbing the covering portion from the side 15 caused to penetrate is amplified.

To sum up, be illustrated, but the present invention is not limited thereto according to illustrated embodiment to optical waveguide of the present invention, the formation of each several part can be replaced as any formation that can play identical function, also can carry out the additional of any formation in addition.

In addition, optical waveguide of the present invention also can be the optical waveguide combining the first embodiment and the second embodiment in the formation of the respective embodiments described above.

And, in the respective embodiments described above, in sandwich layer 13, be provided with two cores 14, but the quantity of core 14 can be more than one or three.

In addition, in the respective embodiments described above, in side covering portion 15, be provided with high-refractive-index regions 151,153, but these high-refractive-index regions also can be arranged in clad 11,12.

In addition, such optical waveguide of the present invention, such as, may be used in the light wiring of optical communication.

In addition, be equipped on substrate by light wiring (light wiring of the present invention) with optical waveguide of the present invention is mixed with existing electrical wiring, can form thus all " opto-electric hybrid board ".In this opto-electric hybrid board (opto-electric hybrid board of the present invention), such as, in an optical device the light signal that connected up by light (core of optical waveguide) is transmitted is converted to electric signal and is transferred to electrical wiring.Thus, can to carry out compared with electrical wiring in the past more fast and more jumbo information transmission in light wiring portion.Therefore, such as, by being applicable to by this opto-electric hybrid board to connect in the bus between the memory storage such as calculation element and RAM such as CPU, LSI etc., thus while the performance improving entire system, the generation of electromagnetic interference (EMI) can also be suppressed.

In addition, described opto-electric hybrid board, such as, can be equipped in the electronic equipment class of the High Speed Transfer Large Volume Datas such as mobile phone, game machine, computing machine, TV, master server.There is the electronic equipment (electronic equipment of the present invention) of opto-electric hybrid board so, the high-performance that internal information processing speed is excellent can be played.

Below, specific embodiments of the invention are described.

1, the manufacture of optical waveguide

(embodiment 1)

First, preparation comprises the sandwich layer formation material of the norbornene polymer with the repetitive that following formula (2) represents.

Next, substrate is coated with this sandwich layer formation material to form aqueous tunicle.Then, drying is carried out to this aqueous tunicle, obtains the layer of sandwich layer formation material thus.

Secondly, by mask by Ultraviolet radiation on this layer, described mask has the opening (window) of the corresponding region of low refractive index that will be formed.Then, in an oven this layer is heated.Thus, the region of irradiation ultraviolet radiation become region of low refractive index (refractive index: 1.54), do not have the region of irradiation ultraviolet radiation become core (refractive index: 1.55) and high-refractive-index regions (refractive index: 1.55), its result, obtains sandwich layer.In addition, the shape of core, high-refractive-index regions and region of low refractive index is arranged respectively to the shape shown in Fig. 2.Wherein, the pitch angle of the high-refractive-index regions shown in Fig. 2 is 45 °.

Then, refractive index is prepared lower than the norbornene polymer of refractive index polymer being used in sandwich layer formation material, the clad formation material of preparation containing this norbornene polymer.

Then, this clad formation material be coated on two substrates respectively and form aqueous tunicle.Then, drying is carried out to these aqueous tunicles, obtains clad respectively.

Then, clad is fitted in the two sides of obtained sandwich layer.Obtain optical waveguide thus.

(embodiment 2)

Except being configured to except the shape shown in Fig. 9 respectively by each shape of core, high-refractive-index regions and region of low refractive index, other operate identically with above-described embodiment 1, obtain optical waveguide.

Wherein, the pitch angle of the high-refractive-index regions 151 ' in Fig. 9 is 45 °.In addition, the interior angle being positioned at core 14 side of high-refractive-index regions 151 ' is 10 °.

(embodiment 3)

Except being configured to except the shape shown in Figure 10 respectively by each shape of core, high-refractive-index regions and region of low refractive index, other operate identically with above-described embodiment 1, obtain optical waveguide.

Wherein, high-refractive-index regions 151 in Figure 10 " length breadth ratio be 1:20.

(embodiment 4)

Except being configured to except the shape shown in Figure 11 respectively by each shape of core, high-refractive-index regions and region of low refractive index, other operate identically with above-described embodiment 1, obtain optical waveguide.

Wherein, the mean grain size of the high-refractive-index regions 153 in Figure 11 is 1 μm.

(embodiment 5)

Except being configured to except the shape shown in Figure 12 respectively by each shape of core, high-refractive-index regions and region of low refractive index, other operate identically with above-described embodiment 1, obtain optical waveguide.

Wherein, the mean grain size of the high-refractive-index regions 153 in Figure 12 is 1 μm.

(comparative example)

Except omitting the formation of high-refractive-index regions and region of low refractive index, and as shown in figure 17, beyond the covering portion forming core and these core both sides in the core, other operate identically with above-described embodiment 1, obtain optical waveguide.

2, the evaluation result of optical waveguide

By method shown below, measure the light intensity of the exiting side end face of the optical waveguide obtained by each embodiment and comparative example respectively.

2.1 evaluate the light intensity from covering portion outgoing

Figure 13 is the figure of the assay method for illustration of the light intensity from the outgoing of optical waveguide covering portion.

In the method, first at the light incident side of the optical waveguide 10 as determination object, configuration diameter is the incident side optical fibers 21 of 50 μm.This incident side optical fibers 21 is connected with the light-emitting component (not shown) for light being incided optical waveguide 10, and the optical axis of the core 14 of its optical axis and optical waveguide 10 is configured in same.In addition, incident side optical fibers 21 can along the light incident side end face 10a of optical waveguide 10, to the identical faces of sandwich layer 13 in scan.Wherein, this sweep length is set as the distance respectively to 250 μm, both sides centered by the optical axis of the core 14 of optical waveguide 10.

On the other hand, at the light exit side of optical waveguide 10, be configured with the exiting side optical fiber 22 that diameter is 200 μm.This exiting side optical fiber 22 is connected from the photo detector (not shown) of the light of optical waveguide 10 outgoing with for receiving, and its optical axis is positioned at the position offseting 125 μm from covering portion 15 side, optical axis direction side of the core 14 of optical waveguide 10.

When measuring light intensity, if scan incident side optical fibers 21 while injection light, then arrive exiting side optical fiber 22 by a part for the light in optical waveguide 10.By measuring the light intensity now inciding exiting side optical fiber 22, have rated the relation between the position of incident side optical fibers 21 and the light intensity inciding exiting side optical fiber 22.

In this evaluation result, representatively the evaluation result of embodiment 1 ~ 3 and comparative example is represented in fig .15.Wherein, the transverse axis of Figure 15 represents with the position of the optical axis of the optical waveguide core incident side optical fibers that is benchmark, the light strength ratio (loss) that it is benchmark that the longitudinal axis represents with the light intensity (light intensity when making the optical axis of incident side optical fibers consistent with the optical axis of exiting side optical fiber and the core of optical waveguide) come by the core transmission of optical waveguide.

From Figure 15 clearly, in the optical waveguide obtained by comparative example, when with the core optical axis of optical waveguide for benchmark, when incident side optical fibers is positioned at the position near 80 ~ 200mm, light strength ratio is large especially.It can thus be appreciated that in the optical waveguide of comparative example, the light inciding side covering portion transmits with almost identical with core intensity.

On the other hand, in the optical waveguide obtained by each embodiment 1 ~ 3, overall light strength ratio is all less.That is, in the optical waveguide of each embodiment 1 ~ 3, the light inciding side covering portion can significantly be decayed, therefore, it is possible to obtain sufficient S/N ratio.

In addition, although not shown, when comparing embodiment 4 and embodiment 5, the result of embodiment 5 is better.Its reason is speculated as: due in embodiment 5, be irregularly configured with the cause of granular high-refractive-index regions.

The evaluation of 2.2 pairs of crosstalks

Figure 14 is the figure of the evaluation method for illustration of crosstalk.

In the method, first, at the light incident side of the optical waveguide 10 as determination object, the incident side optical fibers 21 of configuration diameter 50 μm.This incident side optical fibers 21 is connected with the light-emitting component (not shown) for light being incided optical waveguide 10, and its optical axis is consistent with the optical axis of the core 14 of optical waveguide 10.

On the other hand, at the light exit side of optical waveguide 10, the exiting side optical fiber 22 of configuration diameter 62.5 μm.This exiting side optical fiber 22 is connected from the photo detector (not shown) of the light of optical waveguide 10 outgoing with for receiving, and its optical axis is configured in in the optical axis the same face of the core 14 of optical waveguide 10.In addition, exiting side optical fiber 22 can along the exiting side end face 10b of optical waveguide 10, to the identical faces of sandwich layer 13 in scan.Wherein, the setting of this sweep length, centered by the optical axis of the core 14 of optical waveguide 10, divides the distance of taking leave of 250 μm, both sides.

When measuring light intensity, if scan outgoing optical fiber 22 while penetrating light from incident side optical fibers 21, then exiting side optical fiber 22 can be arrived by the light of core 14.Now, by the external diameter of exiting side optical fiber 22 being set greater than the external diameter of core 14, the light intensity spilt from core 14 can be measured thus.Therefore, by evaluating the relation between the position of outgoing optical fiber 22 and the light intensity inciding exiting side optical fiber 22, degree of crosstalk is evaluated thus.

In this evaluation result, representatively the evaluation result of embodiment 2 ~ 4 and comparative example is represented in figure 16.In Figure 16, the transverse axis of chart represents with the position of the core optical axis of the optical waveguide exiting side optical fiber that is benchmark, the longitudinal axis represent with the light intensity come by the core transmission of optical waveguide (when the optical axis of exiting side optical fiber and the optical axis of core consistent time light intensity) for the light strength ratio (loss) of benchmark.

Clearly known from Figure 16, compared with the optical waveguide obtained by comparative example, in the optical waveguide obtained by each embodiment 2 ~ 4, the light intensity being positioned at spectrum peak underfooting is all less.This spectrum peak is equivalent to the intensity being transmitted the light come by core.Therefore, in other words, compared with comparative example, with respect to the light intensity that core transmission comes in each embodiment 2 ~ 4, transmit by covering portion the light intensity come less, confirm crosstalk phenomenon and relatively reduce.

Industrial applicibility

Optical waveguide of the present invention, the covering portion comprising core and adjoin with this core and arrange, wherein, above-mentioned covering portion comprises: region of low refractive index, and refractive index contacts lower than described core and with described core; And multiple high-refractive-index regions, refractive index is higher than this region of low refractive index and separated by this region of low refractive index and described core, and the plurality of high-refractive-index regions is dispersed in described covering portion, or is fitly arranged in described covering portion.Therefore, it is possible to suppress the light inciding covering portion to be directly transferred to the phenomenon of ejecting end, and reduce light intensity when this light is received by photo detector.Thus, improve the S/N ratio of the light transmitted in optical waveguide, suppress crosstalk etc., thus the optical waveguide can carrying out high-quality optical communication can be provided.In addition, by having this optical waveguide of carrying out high-quality optical communication, the wiring of high performance light, opto-electric hybrid board and electronic equipment can be provided.Therefore, optical waveguide of the present invention, light wiring, opto-electric hybrid board and electronic equipment have the utilizability in industry.

Claims (11)

1. an optical waveguide, multiple core with transmission light and the covering portion arranged each other at this core, is characterized in that,

Described covering portion has: refractive index is lower than the refractive index of described core and the region of low refractive index contacted with described core; And refractive index is higher than the refractive index of this region of low refractive index and the multiple high-refractive-index regions in pelletized form when overlooking separated by this region of low refractive index and described core,

Described multiple high-refractive-index regions is the region be dispersed in regularly or brokenly in described covering portion, be with the region that formed in the same manufacturing process of described core.

2. optical waveguide as claimed in claim 1, wherein, described multiple high-refractive-index regions is made up of the material with described core identical type.

3. optical waveguide as claimed in claim 1, wherein, described multiple high-refractive-index regions, based on being dispersed in described covering portion, makes to carry out irregular scattering by the light of described covering portion.

4. optical waveguide as claimed in claim 1, wherein, described each high-refractive-index regions has concavo-convex on its profile.

5. optical waveguide as claimed in claim 1, wherein, the refractive index of described each high-refractive-index regions and the refringence of described region of low refractive index are more than 0.5%.

6. optical waveguide as claimed in claim 1, wherein, described multiple high-refractive-index regions is configured to the light incident side end face and the light exit side end face that are not exposed to this optical waveguide.

7. optical waveguide as claimed in claim 1, wherein, this optical waveguide has: the sandwich layer comprising described core and described covering portion; And be separately positioned on the clad on two sides of this sandwich layer.

8. optical waveguide as claimed in claim 1, wherein, being formed using norbornene polymer as main material respectively with described core at least partially of described covering portion.

9. a light wiring, is characterized in that having optical waveguide according to claim 1.

10. an opto-electric hybrid board, is characterized in that, electrical wiring and light according to claim 9 wiring mixing is equipped on substrate and forms.

11. 1 kinds of electronic equipments, is characterized in that, have opto-electric hybrid board according to claim 10.